Method of manufacture of rayon filaments



Jan. 6, 1931. A. E. GUENTHER ET AL 1,787,575

METHOD OF MANUFACTURE OF RAYON FILAMENTS Original Filed May 27, 1926ATTORNEY Patented Jan. 6, 1931 v the required form which may be usedchines.

UNITED STATES PATENT OFFICE ARTHUR E. GUENTHER AND HARRY S. TOOLE, OEBUFFALO, NEW YORK, ASSIGNORS, BY

MESN'E ASSIGNMENTS, TO DU PONT RAYON COMPANY, OF NEW YORK, N. Y., A COR-PORATION OF DELAWARE METHOD OF MANUFACTURE OF RAYON FILAMENTS Originalapplication filed May 27,

1926, Serial No. 111,950. Divided and this application filed October 3,1927. Serial No. 223,826.

This application is a division of our co-pending application Serial No.111,950, filed May 27, 1926. v

This invention relates to a novel and improved method of mapufacturingrayon and more particularly to a method of imparting twist to rayonthread. In spinning rayon by the so-called bucket process the rayon,while still wet from the coagulation bath, is wound into a rotatingbucket where it forms a cake, this winding giving a certain amount oftwist to the thread. In actual practice this twist amounts to aboutthree turns per inch of length, and that is about the maximum which canbe achieved. Theoretically, an additional twist could be imparted to thethread by increasing the speed of rotation of the bucket, but actuallyit is not possible to thus increase the speed of the machinesufliciently to give the desired result.

We impart an additional twist to the rayon by removing the cake from thebucket and subsequently placing it bodily upon a bobbin on a throwingmachine which is then operated in the manner common to such ma- Thismethod is made possible by the use of a special bobbin of such aconstruction that it may be inserted within the cake of rayon and thecake secured thereon. It is desirable to avoid handling of the rayon asmuch as possible, because each handling means a substantial waste ofmaterial in addition to the cost involved in the expenditure of time.Therefore, we have devised the above method for throwing the rayondirectly from the cake rather than rewinding it and then throwing it.

It is a further object of our invention to provide a bobbin of novel andimproved to receive a cake of rayon in the form in which it comes from abucket and support the ard throwing machine, thus avoiding the necessityof winding the rayon from the cake onto the bobbin before throwing.

In the accompanying drawing we have shown a selected form of the bobbinwhich we employ in the practice of our method and referrlng thereto:

' downwardly in and registering cake upon a stand- Figure 1 is anelevation of a bobbin constructed accordlng to our invention.

Figure 2 is a plan view of the structure shown in Figure 1. a

Figure 3 is a fragmentary vertical section through the structureappearing in Figure 1.

Figure 4 is a fragmentary plan view corresponding to Figure 2 butshowing the parts in different relation.

The bobbin illustrated in the drawing comprises a spindle 1 the lowerpart of which is of standard or ordinary construction adapted to be usedon throwing machines of wellknown commercial types. This spindle supports at substantially right angles thereto a plate 2 having one or moretongues 3 bent from the central aperture therewith flat portions 4 onthe spindle to key the plate to the spindle. Fitted over the stem 5 ofthe spindle is a spool 6 secured in position on the stem by a lock nut 7which is threaded upon the upper end of the stem. A suitable retainingdevice 8 may be employed to. prevent accidental removal of the lock nut.

The spool 6 is provided with a pair of substantially parallel flanges 9and 10 which are provided with vertically aligned apertures 11 and 12 toreceive the ends of the vanes 13. These vanes are preferably in the/formof wires bent to the form shown and having their ends 14 and 15 receivedin the apertures 11 and 12 respectively. This arrangement exemplifiesmeans for pivotally mounting the vanes upon the spool, the vanes beingheld in position by the plate 2.

The vanes are adapted to expand outwardly from the axis of the bobbinand to them substantially tangent to the circle formed by the apertures11.

The plate 2 not only holds the vanes 13 in expanded position and holdsthem firmly against distortion, but also forms a support for the rayoncake and tends to keep the lower layer of filaments in their originalorder thereby preventing breakage and waste.

In operation the cake of rayon in the form in which it comes from thespinning bucket and in either a wet or dry state is placed upon a bobbinconstructed according to our invention as described above. The hub ofthe bobbin is collapsed by turning the spool in the direction of thearrow in Figure 4, wherein the collapsed position is shown. By turningthe spool in an opposite direction to that shown by the arrow the hub ofthe bobbin is 'expanded, the maximum expansion being illustrated inFigures 1, 2 and 3. The upper flange is knurledto form ready means forthe turning operations referred to. WVhen the hub is expanded to aposition where it will securely hold the cake, the lock nut 7 istightened against the flange 10, this nut being knurled for thispurpose. The vanes are then held in proper position to form the desireddiameter of the hub.

After the cake of rayon is mounted upon a bobbin, the bobbin is placedupon a standard throwing machine and the thread therefrom is led toanother bobbin or spool on the machine. When the machine is put inoperation, the thread is unwound onto the lastnamed bobbin thusimparting the additional twist. Throwing machines of this type areWell-known in the textileart, and we have not deemed it necessary toillustrate or to describe thein further.

i The above method forms a manner of imimparting additional twist torayon thread without the necessity of unwinding and winding with itsattendant waste. The twist imparted to the rayon in the spinning bucketis done while the rayon is wet and therefore the amount of twist whichcan be given to the thread without materially decreasing production islimited. However, it may be given the additional twist by the methoddescribed above and it will be seen that this is done in a manner whichis extremely simple and efiicient.

The method used in our invention is made possible by the use of thebobbin formed with an expansion hub. It will be obvious that this bobbinis of a form which may be very cheaply and efficiently made andassembled and in which the number of parts is reduced to a minimum. Thenecessary adjustments are readily effected by a simple turn of the spooland then the parts are locked in the desired position by an equallysimple turn of the lock nut.

We are aware that various changes in details may be made in the practiceof our invention without departing from the scope thereof, and wetherefore do not intend, to

limit ourselves except by the appended claims.

We claim: 1. In the manufacture of rayon the method which comprisescollecting the rayon in a bucket to form a cake, thereby imparting atwist thereto, placing the cake on an expansible bobbin and thenthrowing the rayon to impart an additional twist thereto.

2. In the manufacture of rayon the method which comprises collecting therayon while wet in a bucket to form a cake, thereby imparting a twistthereto, placing the cake on an expansible bobbin when dry and thenthrowing the rayon to impart an additional twist thereto.

In testimony whereof, we have aflixed our signatures to thisspecification. v

ARTHUR E. GUENTHER. HARRY S. TOOLE.

